This invention pertains to the field of N-(4-piperidinyl)-N-phenylamides and -carbamates. In the prior art there may be found some N-(4-piperidinyl)-N-phenylamides and -carbamates having analgesic activity. Among other points of difference, the compounds of this invention differ from the prior art compounds by the nature of the R.sup.1 -substituted, present in the 4-position of the piperidine ring.
The closest prior art may be represented by the following references:
U.S. Pat. No. 3,164,600; PA1 Riley et al., J. Pharm. Sci., 62, 983 (1973); and PA1 Belg. Pat. No. 818.989. PA1 (a) a carboxylate radical represented by the formula ##STR2## wherein R.sup.2 is a member selected from the group consisting of lower alkyl, lower alkenyl and phenylmethyl; PA1 (b) an alkanoyl radical represented by the formula ##STR3## wherein R.sup.3 is lower alkyl; and (c) an oxymethyl radical represented by the formula EQU --CH.sub.2 --O--R.sup.4 PA1 (i) when said R.sup.2 is phenylmethyl, or when said R.sup.4 is a member selected from the group consisting of phenylmethyl and lower alkylcarbonyl, then said L is selected from the group consisting of alkyl, cycloalkylmethyl, 2-arylethyl, 2-aryl-2-(lower alkylcarbonyloxy)ethyl, 2-aryl-2-(lower alkylcarbonyloxy)-1-methylethyl, 2-aryl-1-methylethyl, 1-(arylcarbonylethyl), 3-arylpropyl, 4-phenylcyclohexyl, 2,3-dihydro-1H-inden-2-yl, and lower alkenyl; and PA1 (ii) when said R.sup.4 is hydrogen then said L is other than 2-[aryl(lower alkylcarbonyl)amino]ethyl. PA1 (a) a radical having the formula ##STR5## wherein R.sup.6 is lower alkyl or lower alkenyl; (b) a radical of the formula ##STR6## wherein R.sup.3 is as previously defined; and (c) a radical of the formula EQU --CH.sub.2 --O--R.sup.7 PA1 wherein R.sup.7 is hydrogen or lower alkyl; PA1 (a) a radical of the formula ##STR12## wherein R.sup.2 is as previously defined; (b) a radical of the formula ##STR13## wherein R.sup.3 is as previously defined; and (c) a radical of the formula EQU --CH.sub.2 --O--R.sup.10 PA1 wherein R.sup.10 is a lower alkyl- or phenylmethyl radical, PA1 (a) a radical of the formula ##STR45## wherein R.sup.2 is as previously defined; (b) a radical of the formula ##STR46## wherein R.sup.3 is as previously defined; and (c) a radical of the formula EQU --CH.sub.2 --O--R.sup.14 PA1 wherein R.sup.14 is selected from the group consisting of hydrogen, lower alkyl and phenylmethyl.